Stereotypic behavior in animals (also called xe2x80x9crepetitivexe2x80x9d or xe2x80x9ccompulsivexe2x80x9d behavior) has been defined by some researchers as acts that are repetitive and constant, which may appear to serve no obvious purpose, and may even be injurious. One of the most common of these behaviors is, for example, crib-biting by horsesxe2x80x94grabbing and biting of the feed bin or of parts of the structure in which the horse is housed (also called xe2x80x9ccribbingxe2x80x9dxe2x80x94see U.S. Pat. No. 4,692,451 for a description of this behavior, associated behaviors, and resulting problems). Another common behavior in dogs is compulsive licking of itselfxe2x80x94even to the point of aggravating a sore (xe2x80x9click granulomaxe2x80x9d or xe2x80x9cacral lickxe2x80x9d). Stereotypies may show some degree of variation, and may be unlike the more typical behaviors such as cribbing and licking, in that they have no features of repetitive motion, but are characterized rather by motionless staring or a frozen body position.
The repetitive behaviors of animals and the compulsive behaviors of humans have both responded to treatment with some of the same drugs. See, e.g., regarding treatment of acral lick with drugs that have shown benefit in human obsessive-compulsive disorder (OCD), Rapoport, J. L., Clin. Neurophar. 15: Suppl. 1 Pt A: 261A-262A, 1992; Rapoport, J. L. et al., Arch. Gen. Psychiatry 49:517-521, 1992. See also Smith, K. C. and Pittlekow, M. R., J. Am. Dermatol. 20:860-861, 1989, wherein it was reported that onychophagia and skin picking responded to treatment with (xe2x88x92) enantiomers of opioid antagonists, which have been effective also in compulsive hair pulling in cats, feather picking in birds, acral lick in dogs and cribbing in horses (Dodman, N. H., Vet. International 6:13-20, 1994; Dodman, N. H. et al., J. Am. Vet. Med. Assoc. 193:815-819, 1988; Turner, R., Proceedings of Annual Conference of the Association of Avian Veterinarians: Aug. 31-Sep. 4, 1993, Nashville, Tenn., pp. 116-118). See also U.S. Pat. No. 4,692,451, the contents of which are incorporated herein by reference in their entirety. Studies of this type provide justification for the conclusion that the same underlying physiological processes are involved in causation of the animal and human behaviors. Therefore, they should all respond positively to new methods of therapy.
The invention relates to a method for treating a disorder in animals, variously termed repetitive, stereotypic, or compulsive behavior, and which can also be self-injurious by administering to the animal, by one or more appropriate routes and by appropriate doses, an effective amount of one or more NMDA receptor antagonists. In some cases, the composition comprises one or more NMDA receptor antagonists that are not haloperidol. In some cases the composition comprises one or more NMDA receptor antagonists, and does not comprise an opioid receptor agonist or antagonist which is primarily (xe2x88x92) enantiomer. In some cases the composition comprises one or more NMDA receptor antagonists, but does not comprise an opioid receptor agonist or antagonist of either (+) or (xe2x88x92) enantiomer.
The invention, more particularly, is a method for treating compulsive behaviors in horses, such as crib biting, wind sucking, stall walking, weaving, head bobbing, pawing, tonguing, self-biting, flank sucking, and head shaking, by administering to the horse a composition comprising one or more NMDA receptor antagonists.
In another particular embodiment, the invention is a method for treating compulsive behaviors in dogs, such as compulsive licking (acral lick), tail chasing and whirling, pacing, fly chasing, shadow or light chasing, excessive barking, stone eating, excessive drinking, and excessive eating, comprising administering to the dog an effective amount of an NMDA receptor antagonist.
Also an embodiment of the invention is a method for treating compulsive behaviors in cats, such as wool sucking, compulsive licking, tail chasing, hoarding, pacing, excessive marking, compulsive masturbation, and compulsive aggression.
A further embodiment of the invention is a method for treating compulsive behaviors in birds, such as feather and skin picking.
The invention relates to a method for treating a disorder (or more than one disorder, as it is possible that two or more can occur together) in humans, variously termed repetitive, stereotypic, or compulsive behavior, and which can also be self-injurious, by administering to the human, by one or more appropriate routes and by appropriate doses, one or more NMDA receptor antagonists, thereby relieving the frequency and/or intensity of the compulsion and reducing the frequency and/or intensity of the behavior.
Examples of the human behaviors which can be treated by these methods include, but are not limited to: obsessive-compulsive disorder (with its various manifestations of checking, counting, washing to remove contamination, etc.), trichotillomania, psychogenic excoriation, nail biting, compulsive exercising, smoking compulsion, drug (opioid) addiction, and alcohol addiction. These compulsive behaviors may be related also to compulsive gambling, compulsive shopping, and eating disorders.